Temperature control of a jacketed-chamber of melt spinning machine

ABSTRACT

The heating powers of the heaters positioned at the both ends of a hermetically sealed and heat-insulated chamber enclosing a group of spinning heads and having electric heaters for heating a heating medium therein, wherein every spinneret assembly is positioned between said heaters, are reduced to 30-90 percent of those of the others, the currents supplied to said heaters being all at once on-off operated by means of a temperature controller.

United States Patent [72] lnventors Haruki Takizawa;

Nobuo Muramatsu, both of Matsuyama-shi,

Japan [21 Appl. No. 876,877

[22] Filed Nov. 14, 1969 [45] Patented Dec. 7, 1971 [73] Assignee Teijin Limited Kita-ku, Osaka, Japan [32] Priority Nov. 26, 1968 [33] Japan [54] TEMPERATURE CONTROL OF A JACKETED- CHAMBER OF MELT SPINNING MACHINE 2 Claims, 7 Drawing Figs.

[5 2] US. Cl. 219/480, 2 19/3 88 [51 1 1nt.Cl 1105b 3/02 [50] Field otSearch 219/388,

[56] Relerences Cited UNITED STATES PATENTS 1,252,813 H19 1 8 Kochendorfer 219/388 1,519,287 12/1924 Woodson 219/388 1,878,522 9/1932 lpsen et al 219/388 2,864,931 12/1958 Stoddard et al. 219/388 2,952,097 9/1960 Atkeson 219/388 X Primary Examiner-Bernard A. Gilheany Assistant Examiner-F. E. Bell Attorney-John Lezdey ABSTRACT: The heating powers of the heaters positioned at the both ends of a hermetically sealed and heat-insulated chamber enclosing a group of spinning heads and having electric heaters for heating a heating medium therein, wherein every spinneret assembly is positioned between said heaters, are reduced to 30-90 percent of those of the others, the currents supplied to said heaters being all at once on-off operated by means of a temperature controller.

TEMPERATURE CONTROL OF A JACKETED-CI-IAMBER F MELT SPINNING MACHINE This invention relates to a method for controlling the temperature of a hermetically sealed and heat-insulated chamber used in melt spinning process of synthetic polymeric filaments.

Dyeing property of a synthetic yarn, especially filamentary yarn is the most important feature, and it is no exaggeration that dyeing property decides the quality of final product. One of the factors which greatly influence dyeing property is the temperature of melt polymer spun out of the spinneret.

Therefore, a spinning head comprising pipeline, a measuring pump and a spinneret assembly is housed in a hermetically sealed and heat-insulated chamberto keep the temperature of melt polymer constant. The temperature of the chamber is maintained at the set value by means of a controller.

Hitherto, there are two types of such chambers, one of which is heated by vapor or liquid of a heating medium circulated from a central supply-boiler, the other of which by a heating medium sealed therein which is directly heated by a plurality of electric heaters (sheathed heaters) which are generally so arranged that every spinneret assembly may be positioned therebetween, wherein the currents supplied to said electric heaters are all at once on-ofi operated by means of a temperature controller. The former is profitable industrially when a number of jacketed-chambers are heated by single central boiler, but in this case those jacketed-chambers tend to have different temperatures from each other. Therefore the latter is conventionally used.

This invention relates, especially, to a method for controlling the temperature of a chamber which is hermetically sealed and heat insulated of the latter said type. Such chamber has a heating fluid taken in lower half thereof and a vacuumized space in upper half thereof. Accordingly a heating fluid heated by above-mentioned heaters, the vapor of the heating fluid occupies the upper space and the temperature thereof becomes uniform because the pressure thereof is as same as the vapor pressure of the heating fluid and this pressure is uniform in the space. In the other hand, the temperature of the heating fluid in not uniform in the chamber because of insufficient stirring only by convection. Therefore a group of the spinning heads, a part of which are heat-exchanged with the heating fluid tend to to have different temperatures individually, and dyeing properties of spun-out filaments are different at every spinning head.

The object of this invention is to provide a method for controlling the temperature of the chamber which eliminates nonuniformity of the temperature and all the troubles connected with dyeing properties of the filaments.

The above objects are accomplished according to the present invention by reducing the heating powers of the heaters positioned at the both ends of the chamber.

The feature and advantages of the invention will be better understood from the description of an embodiment thereof, illustrated in the appended drawings, wherein FIG. 1 represents a horizontal sectional view of a hermetically sealed and heat insulated chamber and a group of spinning heads therein of a spinning machine of double-side built type.

FIG. 2 represents that of one-side built type,

FIG. 3 represents a vertical sectional view of the same in FIG. 2,

FIG. 4 shows electrical connections according to this invention,

FIG. 5 and FIG. 6 illustrate in graphic form the temperatures of the polymer spun out of the spinning heads in FIG. 2, and

FIG. 7 illustrates that according to this invention.

Referring now to the drawing, in FIG. 1, FIG. 2 and FIG. 3, molten polymer is delivered to a group of spinneret assemblies 2 to be spun out as filaments l3 therefrom, through a treelike connected pipeline 1, A measuring pump 4 which supplies continuously, under high pressure a constant volume of molten polymer is mounted in the midst of each pipeline 3 connected by means of a gasket 12 to a spinneret assembly 2 comprising of a spinneret 5, a gasket 6, a bridge plate 7, a screen 8, a sand filter 9, a plug 10 and a holder II. In this case a group of spinning heads, each of which is comprising of a pipeline 3. a measuring pump 4 and a spinneret assembly 2, arehoused for temperature control in a chamber 14 coveredwith insulating panels (not shown). This chamber I4 has a vacuumized space A in upper half thereof and a heating fluid B in lower half thereof heated by electric heaters 15 which are so arranged that every spinneret assembly 2 may be positioned therebetween and the currents supplied to said heaters IS are all at once on-off operated by means of a temperature controller (not shown) to which temperature signal of the chamber I4 detected by a temperature sensor (not shown) is fed back.

In prior art, all of said electric heaters I5 had the same heating capacities and the same supplied currents. As a result, the chamber 14 had, we found, nonuniformity of the temperature and thereby the temperatures of the polymers spun out of the spinneret assemblies 2 positioned at the both ends of the chamber 14 were higher than those of the others.

According to this invention, the heating powers of the heaters positioned at the both ends of the chamber 14 are reduced to 30-90 percent of those of the others to eliminate said nonuniformity of the temperatures. For that, the heating capacities or, preferably, supplied currents of the heaters at the both ends of the chamber I4 may be adjusted at a value between 30 percent and percent of those of others.

In the embodiment illustrated in FIG. 4, the supplied currents of the heaters at the both ends of the chamber I4 can be varied independently of those of the other heaters by adjusting current regulators 19, 20 respectively and the current common to regulators 19, 20 is on-off controlled by the control switch 18 which is operated by a temperature controller 17, to which the temperature signal of the chamber 14 detected by a sensor 16 is feedbacked, so that the temperature of the chamber 14 is maintained at the set value of the controller 17. The current regulator I8 is adjusted considering controlling property, while the current regulator 19 is adjusted so that the temperatures of the polymers in every spinneret assembly 2 which can be measured by taking away the spinneret 5 out of the spinneret assembly 2 and inserting a temperature sensor into the bridge-plate 7 in the spinneret assembly 2, may be uniform.

In this embodiment of the present invention, a relay is used as control switch 18, but solid-state switch, such as SCR, may be preferably used.

This control switch 18 can be provided at every heater 15 in the place of said relay, in this case all switches must be all at once on-off operated.

FIG. 5, FIG. 6 and FIG. 7 shows the temperatures of the molten polymer spun out of each spinneret assembly of one side builded spinning machine wherein FIG. 5 illustrates that in prior art, FIG. 6 illustrates that in the case that the heaters positioned at the both ends of the chamber are not used and FIG. 7 illustrates that according to this invention.

Hitherto, the temperatures of the molten polymers spun out of the spinneret assemblies housed in the single chamber had apparently in these graphs nonuniformity in excess of 5 C., namely the temperatures of the polymers spun out of the spinneret assemblies positioned at the both ends of the chamber are higher than those of the others, while without the heaters positioned at the both ends of the chamber, the former tem peratures are lower than the latter temperatures.

However, according to this invention, nonuniformity of the above mentioned temperatures is eliminated as illustrated in FIG. 7

Therefore this invention contributes a great deal to improve the property, especially dyeing property, of filaments.

We claim:

1. In a method of controlling the temperature of a hermetically sealed and heat-insulated chamber, the chamber enclosing a plurality of electric heaters for heating a heating medium temperature controller; and controlling the heaters positioned at the ends of said heater row to reduce their heating power to 30-90 percent of the heating power of the other heaters in said heater row.

2. A method claimed in claim 3, wherein the current supply to the heaters located at the ends of said heater row is adjustable independently of the current supply to the other heaters. 

1. In a method of controlling the temperature of a hermetically sealed and heat-insulated chamber, the chamber enclosing a plurality of electric heaters for heating a heating medium therein and arranged in at least one row, and a plurality of spinning heads arranged in at least one row, each spinning head comprising a pipeline for delivering spinnable material, a metering pump disposed in the pipeline and a spinneret assembly connected to the lowermost end of said pipeline; each spinning head positioned between two electric heaters; the steps of controlling the temperature of said heating medium by simultaneously operating all said heaters by means of a temperature controller; and controlling the heaters positioned at the ends of said heater row to reduce their heating power to 3090 percent of the heating power of the other heaters in said heater row.
 2. A method claimed in claim 3, wherein the current supply to the heaters located at the ends of said heater row is adjusted independently of the current supply to the other heaters. 